mlxsw: minimal: Fix deadlock in ports creation

Drop devl_lock() / devl_unlock() from ports creation and removal flows
since the devlink instance lock is now taken by mlxsw_core.

Fixes: 72a4c8c9

 ("mlxsw: convert driver to use unlocked devlink API during init/fini")
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/f4afce5ab0318617f3866b85274be52542d59b32.1660211614.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>